Mobile, desktop and server computing devices of today typically employ power management schemes to promote and implement energy efficiency for the devices. A common power management scheme is the Advanced Configuration and Power Interface (ACPI) open-industry specification that was co-developed by Hewlett-Packard™, Intel™, Microsoft™, Phoenix™, and Toshiba™.
According to the ACPI specification, an ACPI-compliant device can be in one of the seven power states S0-S5 and G3. The S0 power management state (hereinafter, “power state”) denotes the power-on state of the device, whereby the device's operating system (OS) and applications may be running with its central processing unit (CPU) executing instructions. The next four power states S1 -S4 denote various sleep modes. In the S1 power state, power to the CPU and random access memory (RAM) is maintained, and other components in the device are powered down if they do not indicate the need to remain on. In the S2 power state, the CPU is further powered off. In the S3 power state, also known as “standby” in Microsoft™ Windows OS devices, RAM remains powered, but most other components in the device are powered down. In the S4 power state, also known as “hibernation” in Microsoft™ Windows OS devices, RAM is also powered off; however, all of its content is saved to a hard drive to preserve the states of the OS, applications, open documents, etc. Thus, the S2-S4 power states are referred herein as the sleep states because the CPU is powered off.
The next power state is S5, also known as a “soft off,” wherein the CPU and RAM are powered off, but some components remain powered so the computer can wake up from various inputs such as a keyboard, local area network (LAN), or a universal serial bus (USB) device. However, a boot procedure is required to bring the device back up online from S5 to S0 state. The last power state is G3, which is the opposite of the S0 power state. The G3 power state is also known as “mechanical off,” wherein all components (except for those running on small batteries) in the device is powered down, and the device's power consumption is substantially zero. Thus, the S5 and G3 power states are referred herein as the power-off states.
Not all ACPI-compliant devices implement all ACPI power states. For example, most home personal computers (PCs), such as desktop and laptop PCs, that run Microsoft Windows™ operating systems (OS'es) are provided with four states, S0 for power on, S3 for standby, S4 for hibernation, and G3 for complete power off or mechanical off.
In a typical computing device with an OS that supports an application launch from an ACPI state (or a power state of any other power management scheme), if the device and its OS go into a sleep mode in S2-S4 states or a power-off mode in the S5-G3 states, the user must “wake up” or power up the device and most often has to login before proceeding to the application launch. Thus, the user must waste additional time waiting for the ACPI-compliant device to achieve the S0 power-on state for the OS to be fully functional in normal mode before a desired application can be manually or automatically launched from within the OS in the normal mode. As understood and referred herein, an OS when operating in its normal mode in a computing device provides full functionalities to manage the sharing of resources of the computing device and provide users with an interface to access such resources. An example of an OS normal mode is the normal mode (as opposed to, for example, the safe mode) of Microsoft Windows OS products.
The aforementioned additional time delay for device wake-up or power-up is especially pronounced when the device is initially in either the S5 or G3 state, whereupon a command from the user, the device must implement a boot procedure or sequence to start various initialization procedures and tests, such as a power-on self-test program (POST) and a basic input output system (BIOS) program in the device's firmware, and to load the OS. Thereafter, the desired application may be launched from within the OS. Consequently, such a time delay reduces the user's productivity as the user must wait for the boot procedure to complete and the desired application to launch. It also produces a negative effect on the user's overall experience with the computing device.
Furthermore, when the user wishes to close an application and place the ACPI-compliant device in a deep sleep mode in the S4 or S5 state, or a power off mode in the G3 state, the device may not power down properly if other features and/or applications remain running with the device's OS. This is not safe and may corrupt one or more of the running features and applications.
There exist solutions that allow direct launch of an application through a partitioning of the device's main memory to have a main OS for a normal booting procedure and a normal running of applications within the OS and a second OS that can directly access the direct-launch application without having to go through the normal booting procedure in the main OS. Because the second OS only needs to launch one application, it needs not go through the typical extensive boot procedure to support the single-application launching. Thus, it is able to boot up the device and launches the application quickly. For example, an ACPI-compliant device may have one or more hardware direct-launch buttons thereon to allow a user to directly launch an application particular to each button. When the user presses, or otherwise activates, a direct-launch button, the device will be booted up by the second-OS partition, which then automatically launches an application corresponding to the activated direct-launch button. Consequently, these existing solutions employ at least two OS'es and two partitions for a device, which further complicate the design, manufacturing, and reliability of such a device.
Accordingly, there is a desire to provide more simplified solutions that can continue to implement energy efficiency of computing devices while increasing a user's positive experience with such devices.